Cutting instrument



prl l2, 1949. G. w. JOHNSON CUTTING INSTRUMENT Filed Dec. 15, 1945 ATT RN EY Patented Apr. 12, 1949 UNITED STATES ITE-NT 41"' 'FICE 4 Claims.

'This vinvention `relates .to Ycutting devices, and particularly to v.hand-cutting tools for cutting, grooving and marking paper and the like.

The obj ect of the inventionl is to provide a handcuttingltoolvwhich will-be simplein structure and efficient and safe in operation with a resiliently held shield automatically yielding to eXp-ose the cutting edge only when in position against the surface of the material to be cut or marked.

Further objects of the invention, particularly in the yformation of the shield device for easy removal and replacement will appear from the following specification taken in connection with the accompanying drawing in which Fig. 1 is a side view of a typical cutting tool embodying the invention with the shield portion shown cut away on one side;

Fig. 2 is a view similar to Fig. l showing the removal or replacement of the shield;

Fig. 3 is a plan view of the device shown in Fig. 1;

Figs. 4 and 5 are transverse sectional views taken on the line 4-4 and line 5 5, respectively, of Fig. 1;

Fig. 6 is a view similar to Fig. 1 showing a modification; and

Fig. 7 is a transverse sectional view taken on the line 'I-l of Fig. 6.

In the embodiment of the invention shown in Fig. 1 a handle portion Ill is provided with a cutter blade I I, the shank I2 of which is rigidly xed in the handle. The blade I I has an offset cutting edge I3 and an inclined front edge I4 forming a sharp point I5. Such a blade may be used, for instance, in the cutting and trimming of wall paper, wrapping paper, cloth, etc.

To protect the user against accidental :contact with the cutting edge or point, a shield is provided of `folded sheet metal shaped with two sides enclosing the blade II and extending beyond the edges of the blade in the normally inoperative position shown in Fig. 1. This shield has the side portions 2| connected by the bend 22 which in normal position of the shield runs substantially parallel to the upper edge 23 of the cutting blade. The shield is pressed downward by the spring 24 anchored in the blade shank at 25 and engaging above the pin 25 which bridges across between the sides of the shield near the upper portion thereof as shown. A cooperating pin 21 transverse of the shield at the front portion thereof engages against the seat edge 28 of the front recess 29 of the blade and holds the shield 20 in place with its lower edge 30 below the cutting edge I3 of the blade.

This. shield '2li is removable and replaceableaas illustrated in Fig. 2 by simply sliding litendwise over the blade and is held `in place by ithe latch spring it engaging inthe recess35 ofthe Ashield in the assembledposition (Fig. 1f) lnzpositioning of the shield on the blade, the inner end slides under the inclined finger piece 36 of the spring lifting the spring,'which then automatically snaps back into the recess 35, and to release the shield it is only necessary to lift the finger piece 36 to clear the recess. During the assembly of the shield the upturned end 38 of the spring 24 slips over the top of the pin 2B in the position shown in Fig. 1.

A simple release and pull of the shield thus releases the cutting blade for inspection and sharpening, and the shield is easily replaced by a simple return movement.

Various forms of blades and cutting edges may be used, and in Figs. 6 and '7 the cutting wheel. 4I) is mounted in the holder 4I of folded sheet metal having a shank portion l2 fastened in place in the handle 43. The shield 44 is similar to the shield 2li being latched in place by a spring 45 engaging recess 46. The shield is resiliently pressed downward by spring 41 anchored in the shank i2 and engaging the pin 48 which in turn lengages the top of the shank 42 to limit the downward movement of the shield and bring its edge 4S somewhat below the cutting edge of the wheel 4B. A pin Eil across the end of the shield limits the upward movement of the shield by engagement with the projection 5I of the holder 4I.

The shield 44 is removable and replaceable in the same manner as the shield 20, and similarly resiliently encases the cutting edge against accidental injury to user and marking of parts of articles with which the tool comes in contact when not in use. An extra blade 55 may be pressed in place in a slot in holder 42 as shown, to be available for straight edge cutting on removal of the shield 44.

While the application of the shield has been illustrated in connection with a straight edge blade and a cutting wheel, the principle of the invention is applicable to other cutting or marking tools, for instance, a cuttingI Wheel similar to that shown in Figs. 6 and '7 may have a perforating instead of a cutting edge, and other modications of the cutting device corresponding to the shape of the shield may be made within the scope of this invention as dened in the appended claims.

I claim:

1. The combination with a hand cutting tool comprising a handle and a blade member carrying an operative cutting edge, of a shield movably mounted on said blade member and having protective side edges adapted to extend beyond said operative edge of said blade member, an engageable and releasable latch means between the rear end of said shield and said tool comprising a projection and a mating recess automatically interlocked by movement of said shield along said blade toward said handle and detachably retaining said shield for pivotal movement on said blade, and engageable and releasable spring means between said shield and said tool comprising a. longitudinally extending spring and a, cooperating member automatically interengaged by said movement of said shield along said blade toward said handle and acting to resiliently hold said shield in predetermined position with its protective side edges protruding beyond the said edge of said blade member and adapted to yieldingly shift with the said material and expose said edge of said blade member.

2. A hand-cutting tool as set forth in claim l in which there are cooperating parts on the shield and blade members limiting the shifting move- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 365,714 Warner June 28, 1887 612,945 Hockerson, Jr Oct. 25, 1898 2,376,887 Walters May 29, 1945 FOREIGN PATENTS Number Country Date 93,583 Germany Aug. 19, 1897 

